Diffusion of silicon in titanium dioxide thin films with different degree of crystallinity: Efficiency of TiO2 and TiN barrier layers

Author(s)

Libardi, J. ^[1] ; Grigorov, K. G. ^{[1, 2]} ; Massi, M. ^[3] ; da Silva Sobrinho, A. S. ^[1] ; Pessoa, R. S. ^[4] ; Sismanoglu, B. ^[1]

Affiliation

^[1] Technol Inst Aeronaut ITA, Dept Phys, Sao Jose Dos Campos, SP - Brazil

^[2] Space Res & Technol Inst, Acad G Bonchev Str Bl 1, Sofia 1113 - Bulgaria

^[3] Fed Univ Sao Paulo ICT, Sao Jose Dos Campos, SP - Brazil

^[4] Univ Vale Paraiba Univap, Av Shishima Hifumi 2911, BR-1224400 Sao Jose Dos Campos, SP - Brazil

• Document type: Journal article
• Source: VACUUM; v. 128, p. 178-185, JUN 2016.
• Web of Science Citations: 4

Abstract

Two kinds of reactively sputtered titanium dioxide films with columnar and fine-grained structures were investigated as diffusion barriers, preventing the silicon diffusion. The only differences in the deposition conditions were the oxygen percentage concentration (OC) in the discharge, kept for 10% and 30% of the total working pressure. The resulting films were found to have different thicknesses being 800 and 240 nm for 10% and 30% OC, respectively. The films were studied by X-Ray diffraction spectrometry (XRD) and their composition by Rutherford Backscattering Spectrometry (RBS). In order to describe the diffusion processes, the two batches were annealed up to temperature of 800 degrees C. The diffusivity from 300 degrees to 800 degrees C is D(m(2)/s) = 2.43. 10(-18) exp{[}-(15 kJ/mol)/(RT)] and D(m(2)/s) = 2.36. 10(-18) exp{[}-(18.4 kJ/mol)/(RT)] for (10% OC) and TiO2 (30% OC), respectively. The physical meaning of the derived diffusion parameters are discussed in view of the crystalline peculiarities of the obtained films. Arrhenius plots show clearly that higher activation energy is characteristics for films with better-packed crystallites. These results are compared with known diffusion barrier layer such as TiN. (C) 2016 Elsevier Ltd. All rights reserved. (AU)

• FAPESP's process: 10/11294-7 - Deposition of TiO2 Thin Films using plasma technology for applications in microelectronics
• Grantee: Juliano Libardi
• Support Opportunities: Scholarships in Brazil - Post-Doctoral